Macro and trace elements bioavailability in vegetable and herbal species from polluted and control areas

Several plant species (R. acetosa, S. oleracea, U. dioica, А. Sativum, A. cepa and P. hortense) were studied to determine macro and trace elements content trends and their bioavailable forms. The total contents of 21 elements: (1) macro biogenic elements (Ca, K, Na, Mg, and P), (2) elements that have the essential functionality in microcontents (Ba, Cr, Li, Cu, Fe, Mo, Mn, Sr and Zn), and elements that are toxic even in traces (Ag, Al, As, Cd, Ni, Pb and V) were determined with the application of atomic emission spectrometry with inductively coupled plasma (ICP-AES). The total concentrations were measured in samples after total mineralization with concentrated nitric acid and hydrogen peroxide in a microwave digestion system. Three extraction methods were implemented for determination of bioavailable contents in the soil: (1) Extraction with deionized H2O that provides information on the actual availability of the elements in the soil solution; (2) Extraction with 0.1 M HCl. (3) Extraction of the soluble species of trace elements in a mixed buffered solution (pH= 7.3) of triethanolamine (TEA, 0.1 mol L−1) with CaCl2 (0.01 mol L−1) and diethylenetriaminepentaacetic acid (DTPA, 0.005 mol L−1), which is often recommended for extraction of toxic or biogenic metals. Translocation enrichments were obtained for As, Cd, Cu, Ni, Pb and Zn. All of the analyzed species show potential for phytoextraction and phytostabilization of Cd, Cu, Pb and Zn